Optical framing projector assemblies are widely used in the architectural and theatrical lighting industries. Optical framing projector assemblies can be surface mounted onto the finished surface plane of a structure or recessed behind the finished surface plane of a structure. A large opening in the finished surface plane of a structure is required to facilitate side access to the various adjustment and locking features. After a recessed installation is complete, a removable trim plate covers the large opening in the finished surface plane of a structure and the trim plate includes an aperture opening for the light path to pass through.
Optical framing projector assemblies are used when precise illumination is desired. The subject is lit or pattern image projected by an optical framing projector assembly, making the subject appear magically illuminated. The distinguishing characteristic of an illumination produced by an optical framing projector assembly is that this magical light stops precisely at the edge of an illumination zone. In this high contrast binary illumination, the subject alone is bathed in light, while the surrounding area is dark.
An optical framing projector assembly confines and shapes light using a light mask. The confined and shaped light is focused using an objective focal lens resulting in a customized illumination zone shape on a surface where it can be seen. The light mask in an optical framing projector assembly can take many forms known and used today. The forms range from field adjustable light masking shutters, or mechanically adjusted iris-type devices, to pre-manufactured light masking plates or light masking plates that are created by technicians in the field as they cut or scrape away light masking material to allow shaped light to pass through. Light masks are used to for several purposes. For example, to create four-sided rectilinear shapes, such as for a painting; to create images, such as custom logos, stars, clouds, etc.; to follow the contour of irregularly shaped objects such as sculpture; and to project multiple beams of light from one projector having a light mask plate with multiple openings.
The light mask is positioned within a light mask slot located within the light mask gate of an optical framing projector assembly. The light mask gate is designed to receive one or more of the light mask forms described.
The light mask gate in an optical framing projector assembly is sometimes designed to rotate around the light axis. Projector systems that include a gate rotation feature will also include a gate rotation locking system. The gate rotation and locking features facilitate adjustment for various light mask forms in cases where the optical framing projector assembly is installed horizontally offset in relation to the illumination zone—in order to compensate for the offset distortion between the illumination zone shape and the light masking edge-opening shape.
For systems implementing a gate rotation feature, the light mask gate is rotated during final adjustment of an optical framing projector assembly and then locked into position using at least one fastener with a fastener body affixed to the side of a projector with the fastener orientated perpendicular to the light axis. Side access to the gate rotation locking fastener with the fastener orientated perpendicular to the light axis in a recessed optical framing projector assembly installation can be one of the causes for a larger opening requirement in the finished surface plane of a structure. The large, unsightly opening is necessary to give the installation technician sufficient access to work around the optical framing projector assembly—providing ample room for a hand and/or other fastener driver to be positioned perpendicular to light axis.
One specific light mask form known and used today is a light masking shutter. Usually four light masking shutters are installed perpendicular to the light path axis within the light mask slot of a light mask shutter gate. To reduce the risk of light masking shutters jamming into one another, a separator plate may sometimes be implemented to separate pairs of light masking shutters. Two opposing light masking shutters would then share one plane of the separator plate, and the other two perpendicular light masking shutters 180° off will share the opposite side of the separator plate on a different parallel plane.
Most optical framing projector assemblies do not include a shutter locking mechanism to secure light masking shutters. Each shutter is adjusted while often accidentally moving an opposing, previously adjusted light masking shutter resulting in illumination zone errors from a light masking shutter being miss-aligned to the desired illumination zone edge. Technicians must sometimes lock shutters into position using a wedge installed into the light mask slot positioned perpendicular to the light axis.
The objective focal lens is normally installed within an objective focal cone. The objective focal lens can be provided as a limited one-size-for-all, or be custom chosen to match the focal length requirements of individual installations. For a custom focal length, the goal is to produce an outbound light beam that is the correct diameter for the application by choosing one or more lenses with the correct focal length.
A light emitting diode or fiber optic light source is sometimes used, however, the light source for an optical framing projector assembly is usually halogen or metal halide. Both generate high levels of heat. The light source engages a lamp holder and the lamp holder is usually fastened to a back cap. The back cap often includes a closed design to eliminate light leaks into a recessed housing or onto the finished surface plane of a structure. Optical framing projector assemblies also often include a closed lamp housing design to minimize light leaks into a recessed housing or onto the finished surfaces plane of a structure.
A hot light source, combined with a closed lamp housing and closed back cap cause many optical framing projector assemblies to operate at very high temperatures. The high temperature makes it extremely difficult for technicians to adjust optical framing projector assemblies. The problem is exasperated when a closed design optical framing projector assembly is installed into a recessed housing behind the finished surface plane of a structure.
When adjusting the manually adjusted light masking shutter, technicians are exposed to the risk of burns.
In sum, current optical framing projection systems do not provide sufficient safety or safe access for technicians to work with or work around optical framing projection assemblies due to high temperature that can be compounded by insufficient opening space when behind a finished surface (unless an architect is willing to provide a large, unsightly space opening in a finished surface). The key objectives of the present invention are to improve technician access and safety when working with optical framing projection assemblies, while also minimizing the need to create large, unsightly openings in finished surfaces of a structure. These key objectives are achieved in the form of forward access adjustment and locking systems, which provides safer and greater access to projection assemblies.